Do you lose image quality...

[Tom Muller]

each time you save a jpeg file at less than 100% quality? Some text in GraphicConverter_manual IMPLIES that you DO lose quality. I tried opening then re-saving a file at VERY low quality numerous times and the overall quality did not appear to change with successive saves. Thanks, Tom

[BillBoyle]

Tom, I think you will find that you lose quality because it recompresses but only after you have changed it and then save the changes. Bill > From: "Tom Muller <flintlock@comcast.net>" <flintlock@comcast.net> > Reply-To: graphicconverterforum@yahoogroups.com > Date: Sat, 18 Jan 2003 16:24:23 -0000 > To: graphicconverterforum@yahoogroups.com > Subject: [graphicconverterforum] Do you lose image quality... > > each time you save a jpeg file at less than 100% quality? Some > text in GraphicConverter_manual IMPLIES that you DO lose > quality. I tried opening then re-saving a file at VERY low quality > numerous times and the overall quality did not appear to > change with successive saves. > > Thanks, > > Tom > > > > To unsubscribe from this group, send an email to: > graphicconverterforum-unsubscribe@yahoogroups.com > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >

[George Slusher]

>each time you save a jpeg file at less than 100% quality? Some >text in GraphicConverter_manual IMPLIES that you DO lose >quality. Yes, you do. >I tried opening then re-saving a file at VERY low quality >numerous times and the overall quality did not appear to >change with successive saves. As Bill implied, you may not have actually been re-saving the file. When you use command-S, Graphic Converter does not save the file unless you have changed something--check the modified dates/times. There are several ways to fool GC into thinking that something has changed without actually changing anything. A simple way is to use command-A to select all the image, then command-Y to trim to the selection. You can then use command-S to save the "changed" file. Of course, keep a copy of the original to compare to the re-saved version. George Slusher/Eugene, OR gslusher@rio.com

[Michael Smith]

What happens when you print a picture that is too big for the page? For example: if I have a 3MB photo at 72 ppi and I go to File>Print, a dialog box says something like"This is too big to print do you want to scale or trim the picture?" What happens if you choose "Trim?" What happens if you choose"Scale?" Does scale resize the picture at its original ppi,in this case 72ppi? Does it resize the picture by increasing the ppi and reducing the picture dimensions (like increasing Resolution in the Picture>Size>Scale dialog with "Scale Picture" unchecked--the resolution, in ppi , increases and the size, in inches, decreases). Or does it reduce the image size and maintain the original ppi, 72 ppi in this case? Many thanks for the best piece of shareware on this planet -perhaps others, I don't know about them. -- Michael Smith ms consulting 508 Second Street Ann Arbor, MI 48103 734.994.6532 ****************************************************************** "Any significantly advanced technology is indistinguishable from magic." -- Arthur C. Clarke ******************************************************************

[Marino Pascal]

Michael Smith wrote: > What happens when you print a picture that is too big for the page? > For example: if I have a 3MB photo at 72 ppi and I go to File>Print, > a dialog box says something like"This is too big to print do you want > to scale or trim the picture?" > What happens if you choose "Trim?" You may lose some parts of the picture. If your picture is a 2x20 panorama and you set it to print a 4x4 you will only print the center and lose the sides. > > What happens if you choose"Scale?" It proportionally scales it. You won't lose any parts of the picture. Frankly the best way to test all that is to choose "Preview" from your printer's dialog box and see how it would lay out on paper without wasting ink and paper. > Does scale resize the picture at > its original ppi,in this case 72ppi? Does it resize the picture by > increasing the ppi and reducing the picture dimensions (like > increasing Resolution in the Picture>Size>Scale dialog with "Scale > Picture" unchecked--the resolution, in ppi , increases and the size, > in inches, decreases). Or does it reduce the image size and maintain > the original ppi, 72 ppi in this case? The monitor can't display more than 72 ppi A perfect print should be at least 300ppi Your print should be 4 times smaller than what you see on the screen. 4 x75 =300 What does this mean? If you have a picture that's 4x16 (inches, centimeters doesn't matter) on screen at 72 ppi you should print it it 4 times smaller i.e. 1x4 Of course this is a matter of taste and you maybe perfectly happy blowing up little pictures. Another way to look at this: You have an image 1600x1200 from a digi camera All diigital cameras output 72ppi With GC choose Picture -> show information Size 1600x1200 pixel Click on pixel Change to inches (or cm) Now it says 22 x 16 inches Say my paper is 11x8 If I tell GC print dialog to resize image to fit page It will print the image 11x8 (minus borders) i.e with half the width , half the height , 72ppi x 2 = 144ppi I'll get a 144ppi print If I tell GC to print resized 25% , the image will be 5.5x4 and 288ppi. A mistake a lot of people make is they shoot high resolution images with their digi cameras, they look too big on the screen and then resize them from 1600x1200 to 640x480 cause that size looks right. Then they get bad prints. Just let the GC print menu do the resizing for you. It will give you the most ppi for the size of your original image and the size of print you choose. There is no need to manually change size and resolution of the actual file to get better prints. You'll do more harm than good. Hope this helps. I've written a related article here: http://locationscout.com/imaging/resolution.html Marino -- ------------------------ Marino Pascal 2525 Crestmoore Pl Los Angeles, CA 90065 323/254-9272 http://LocationScout.com